Rock-drill.



M. A. KNAPP.

ROCK DRILL.

APPLIUATION FILED FBB.7, 1910.

Patented Oct. 24, 1911.

I 5. l y /M//M//M/ 1 50 contiguous to the lower end of the hammer.

` is a second rod or bar which lies be-I UNITED STATES orrnin.-- l

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Application mea February 7, 1510. serial No. Magus.

To lall 'whom it may concern:

a citizen of the United States., residing at- Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Rock- Drills, of which the following is a specification.

My invention relates to the class of rockdrills, and it .has for its object the -provision of a drilling machine or device capable of penetrating rock or other hard vIna-1 terial to. depths to which it has not been practicable to'drill with either churn drillsor. hammer drills; and yfurther to provide'l for the use of much lighter Amachines for? drilling holes to depths now reached by;v

churn drills and the heavier hammerdrills.

My invention' may be briefly stated to conj. sist in a drilling device in which there isy interposed and alined between the hammer' and the drill-bit oneyor more separate bars or rods, each of approximately equal length p to the drill bit.

larged sectional detail showing a practical elevation, of my rock-drill. Fig. 2 is an eni means for coupling the sections ofthe guidetube together, the sections being here Shown 'uncoupled Fig. 3 is a cross section, er1- larged, through the guide tube andv in-i closed rod.

which the drill is operating;

2 indicates, 1n a general Way, the hammer- ."carrying shell or casing in which any suitable arrangement Aof-ports and passages may nexist, which may be necessary to operate thel hammer, through pneumatic or other iuidf pressure. Secured to this shell or casing isl a second section 4 is coupled.

vthe first section 3 of the guide tube, which 5 is the hammer, here shown as of the bar.

a housed within the lower endof the'second` section 4 of the guide tube. y

9 is a rod or bar the upper end of `whichis `tween the lower end of the rsty rod and the rods is of 'approximately equal length to Be it known that I, Moses ARTHUR KNAPL that of the drill bit. I y

Theoretically, and in ractice, initially, the len h offea'ch rod be equal to that of the rill bit, but in view -of the fact` that the latter wears down, this absolute Specification of Letters Patent. Patented Oct. 1911'. i

equality of length cannot be maintained,but'it should be kept as near as possibleand I-have indicated this by the word approximately. When a bar-hammer is used, such as Ihere show, it is best that the approximate equality of' length extend to it also, and that it shall be of'a proximatel'y equal length'to the rods and .t e'drillibit. Also for the best 'row of steel bars of equal len h and approximately equal weight, pl'ac end to end (though not' necessarily in contact)- when struck a blow on one endtran`smits'1blofw throughout the series, with a lo'ssof'but oneJ or two per cent.of its energy foreach con- In the accompanying drawings Figure 1i' -is a View, partly in section and partly lin tact 4in the series.' The tempered steel acts as a.per'fectly,. elasticbdyzlosiiigrbnlyfa the: first rod 'o`r bar 'of the series the'drill hammer',`and' for 'the last rod or bar Yoi? the seriesz I' have substituted the drill bit. 'i I 1 indicates the bore or hole 'in the rack ina true it is obvious that by interposing more sections of drill rods, and by couplmg up more sectionsofguide't-ube, I can 'drill to depths heretofore deemed impractica'ble;

and even at depths to which the ordinary 'hammer or the churn drill iswitted', I can use a much-lighter machine. These advantages lespecially 'adapt my device` for' prospecting. @For example, cont-rast to the small percentageof vloss in my V'device-I have long, striking an' equal weight bar'f' feet long, loses 20% ol?. the energy; aild'aA pound hammer on the same bar, rv'fifhzaf quarter pound tappet inter eSed, 'loses40%5 tof50% mechanical engineers engaged in this work that the eiect of the blow of a hammer on a drill is to carry the latter forward with .the

striking mass. Thisis not the case', except when the soft metal of one is being battered up under the blow.

When there is suiiicient elasticity of the metals to prevent battering, as in all hammer `drill work, the action is that of elastic impact, and the losses of energy are due to the waves of compression traversing the two striking masses. These waves travel apart along the rods from the point of contact and return to meet again onequal length rods. But infinitesimal separation having yet taken place, the two waves dampen each such air or water as may be introduced to clean out the bottom of the hole; and in order to carry this fluid directly to the bot-v .tom of the hole, in the angles of the bitshank, I' prefer to secure to the bit a light' sleeve 12 which telescopes the adjacent guide-tube and forms a confining casing for the Huid. The guide tube sections shouldl be connected by couplings suliiciently rigid to stand the strain, .and yet easy to be made and broken. A. good form of coupling I show in Fig. 2. Upon the end of one tube section is screwedand riveted fast a hard steel nipple 13 in which is made a key-hole aperture 14, one on each side. To the end of the next tube section is screwed and riveted asimilar nipple 15, which is formed with keysr16, oneon each side. -To t the nipples together they are presented side by side and the keys of one passed into the keyholes ofthe other. Then when the drill rods are within, a rigid coupling is made, which will not turn, and can only be dsmembered by removing the interior rods.

In years of experiment the light air-hammer drills have only'partially replaced the heavy two-man machines which reciprocate the whole drill bar. With a long air-pressure cylinder to force them up against the rock, the former, one-man machines, weighing 50 to 100 lbs. With 3 to 5 lb. hammers, can drill upper holes to a depth of 3 to 4 ft., making a very large saving as against the old style of drill. Beyond 3 ft. however, the power of the blow of a short light hammer is largely lost in the vibration of the steel, and cutting speed is rapidly lowered.

'With the more powerful drills, in hard rock,

this vibration causes crystallization of the steel and breakage of drill Shanks, making their use inadvisable in some'cases.

The light hammer machines were first in- I l. y Y 1,006,6614

troduced as hand machines on the lines of the pneumatic riveter. It is impossible, however, for a man to hold up in his hands a machine vibratin a 3 lb. hammer in aA 2 in. cylinder 1000 times a minute. The 20 lb. hand machines with 2 lb. hammers in 11,1 in. cylinders, now on the market, are hard to hold and drill slowly beyond one ft. in depth. Pneumatic riveters, held in the hands of the Workmen are in constant use. They have hammers of to l 1b. in weight. A 20 lb. hand machine with a 1 lb. bar-hammer 10 in. long, could be easily held; and with my composite drill'rod, could cut as fast at 4 ft. depth as one with a short 3 lb. hammer striking a long solid bar. The loss in the latter case is due first to the 2 0 lto 40% loss in impact, but still more to the fact that the slow blow of the heavy drill powders the rock and does not cut as fast as the sharp chipping blow of the lighter drill. with the same kinetic energy.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. In a rock-drill of the hammer type, and in combination with its hammer and drill-bit, a separate rod alined with and in- `mately .equal to that of the drill-bit.

2. In. a rock-drill of the hammer type,

the combination of a drill-bit, a bar-hammer, and al separate rod alined with and intermediate the hammer and drill-bit and in' such contiguty thereto that the blow from one is transmitted through the rod to the other, said rod, bar-hammer and drill bit having approximately equal lengths.

3. Inl a rock-drill of the hammer type, and in combination with its hammer and drill-bit, a series of separate rods alined With each other and with the hammer and drill-bit and intermediate said hammer and drill bit in such contiguity thereto and to each other that the blow from the hammer is transmitted through the rod series to the drill bit, each rod of the series being of a length approximately equal tothat of the drill-bit( 4. In a rock-drill of the hammer type, the combination of a drill-bit, a bar-ham- Amer, and a series of separate rods alined drill-hit, a series of separate rods alined with eachother and withvthe hammer and drill-bitand intermediate said. hammer and drill bit in lsuch. continguity thereto land to each other that the blow from thxe hammer yis transmitted through the rod se ies to the drill bit,` each rod of the series being of a len h approximatel equal'to that of the dr' l-bit, and a gui e-tube for said rods( vformed of sections releasably coupled.

.6. In a rock-drill of the hammer type, the combination of a drill-bit, abar-hammer, a

'series of separate rods alined with each other and with the hammer and drill-bit and intermediate said hammer and drill-bit in such contiguity thereto .and to each other that the'blow from the hammer is trans- Amitted through the rod series tothe drillbit, each rod of the series and the hammer being of 'a length approximately equal to v20 that' of the drill-bit, and a guide-tube for saiifl1 rods formed of sections releasably cou? In testimony whereof I have signed my' name to this specification in the presence of 25 two subscribing witnesses'.

a v MOSES ARTHUR KNAPP. Witnesses:

A. K. Dncon'rr,l WM. F. BoofrH. 

